1. Field of the Invention
The present invention relates to a projection system.
2. Description of the Related Art
Projectors have hitherto widely been used, each of which forms an optical image on a light bulb, such as a liquid crystal panel, according to an input video signal and projects and displays the image onto the outside. The projectors need various adjustment operations such as focus adjustment, keystone distortion adjustment, and zoom adjustment operations to realize excellent display.
One projector is designed to be manually controlled by a user himself using an operation member. There is another projector that captures a projected image of a test pattern or the like and automatically performs various adjustment operations thereon. Japanese Patent Application Laid-Open No. 2006-121240 discusses a projector that detects, from an image captured by a camera unit, the positions of four corners of each of an area, onto which an image is projected, and the positions of four corners of the projected image and carries out calculation thereon, so that zoom ratio adjustment and keystone-distortion adjustment is carried out.
Japanese Patent Application Laid-Open No. 2000-241874 discusses a technique for projecting a predetermined test pattern or an entirely white image is projected onto a screen from a projector, then capturing the image projected onto the screen, and adjusting a focal length and a zoom ratio and correcting keystone distortion.
A type of usage of a projector is stack projection that realizes high brightness by projecting same images onto a single place from a plurality of projectors, respectively, to overlap with one another. Japanese Patent Application Laid-Open No. 2006-245737 discusses an automatic adjustment technique for use in stack projection by two projection display devices. Specifically, two projection units are caused to project test images onto a projection surface at different timings at each of which the test image is captured. Then, image displacement between the each test images of the projection units and keystone distortion are corrected, based on the each captured test images.